1. Field of the Invention
The invention relates to a ceramic liner according to the preamble of patent claim 1. Such liners are used in particular as an inner wall insulation of metallic combustion chambers.
2. Discussion of Background
A ceramic liner of the type mentioned at the beginning is known from DE 195 02 730 A1. The liner there has the purpose of an uncooled detachable liner of a combustion space with ceramic elements which withstand the high mechanical and thermal stresses in a commercial heavy-duty combustion chamber.
For this purpose, the liner comprises at least one wall panel, made of refractory structural ceramic and having at least one through-opening, and a fastening element per opening. The fastening element is fastened by its foot in a metallic holding device fastened on the metallic supporting wall. The head of the fastening element rests in the opening in the wall panel. The fastening element consists of refractory structural ceramic and is resiliently coupled to the holding device. Arranged between the metallic wall and the ceramic wall panel is an insulating layer. Regarded as the advantages are that the liner can withstand very high mechanical and thermal stresses on account of its homogeneity and the material used and that the liner can be disassembled without being destroyed and can therefore be used repeatedly. Furthermore, the resilient coupling of the ceramic structure to the metallic holding construction allows the thermal expansions between metallic and ceramic components or deformations of the insulating layer due to mechanical stresses to be absorbed.
In the case of this known liner, the thickness of this insulating layer is chosen according to the thermal loading of the overall liner assembly. It must be set at such a thickness that the maximum permissible temperatures of the metallic supporting wall are not exceeded. The insulating material can be applied, for example, in the form of prefabricated blocks, an appropriate bore for the mounting of the liner having to be provided in the region of the fastening bolt. Since the mounting distance between two wall panels is determined by the thermal expansions of the wall panels, the insulating material is strengthened in a suitable way on its surface, or otherwise protected, at least in the region beneath the joints of two neighboring panel elements, so that a flushing out of the insulating layer is avoided if there are parasitic hot air flows in the gap. Owing to virtually unavoidable vibrations of the combustion chamber or due to thermal influences, the insulating layer may, however, change its shape. This can lead to a loosening of the fastening, which after some time may result in loss of the insulating layer.